[pepone]

The ci workflow builds the examples after build/publish-local-packages.sh has pushed the freshly built packages into the runner's NuGet global-packages folder, so restore finds the version the examples ask for locally and never contacts nuget.org. On a release branch, the examples then pass CI with a version that is not published, while a user who checks out the branch gets a restore failure. This is how the 0.6.1 version bump went green on 0.6.x (see #4969).

This PR adds a build_examples_with_published_packages job to ci.yml:

• It runs only when the pushed branch or the PR base branch ends with .x. It is skipped on main, where the examples are meant to track the local build, and it comes along when a release branch is cut from main.
• It builds the examples on a clean runner, without the local package publish, so restore resolves the IceRpc packages from nuget.org.
• It turns off the NuGet cache with a new cache input on the setup-dotnet action (default true, so the other callers are unchanged). The cached ~/.nuget/packages can hold locally built packages: a version bump changes the packages.lock.json files and therefore the cache key, and the first build_and_test run with the new key saves the folder after the local publish.
• It reuses the setup-dotnet action, so it picks up each branch's .NET version.

The docfx examples are not concerned: they only compile the snippets of the API reference and track the repository version.

Verification: on main this job shows as skipped. Against 0.6.x (where the diff applies cleanly), all 38 example solutions build with an empty global-packages folder and nuget.org as the only source, restoring the published IceRpc 0.6.1 packages. The job itself runs on 0.6.x once this is cherry-picked there.

Fixes #4970

What's Changed entry

None — CI-only change.

[Copilot]

🟢 Approval recommended

No active review issues are reported for the release-branch CI validation against published NuGet packages.

No open issues 🎉

What changed in this PR

Adds CI validation that release-branch examples build against published NuGet packages, preventing local packages from masking unpublished version references as described in #4970. Main-branch and DocFX example builds remain unchanged.

Changes:

• Adds a clean-runner example build for branches and PR targets ending in .x.
• Adds a default-enabled cache input to the shared .NET setup action, disabling it for the published-package check.

File	Description
.github/​workflows/​ci.yml	Adds the release-branch example build without local package publishing or cache restoration.
.github/​actions/​setup-dotnet/​action.yaml	Makes NuGet caching optional while preserving existing callers’ behavior.

_{Review effort: Balanced}